Magazine owns my voluntarily contributed article?

Hello,
I was wondering if someone who knows the law could help me out here.

Recently, I sent an article of mine to a couple of magazines, some based in the US and others elsewhere. Now, I said in my letter that if any institution was interested in publishing my piece, I would like to know beforehand. Two magazines (one in the US, one in the UK) responded, saying they were interested, but at the same time, I came to know that another magazine (based in the US) had already printed my article without informing me. Although I did not have any problem with that, I was now confused as to whether I could let the other two magazines who had actually replied, print my piece or not. When I called those who had printed my piece to ask regarding this, they said sure, we give permission, but the other magazines must cite us as the source. I don't agree with them, because, firstly, I requested to be informed before publication of my article which they didn't, and secondly, because I did not receive any monetary compensation or anything of the sort from the magazine or even any contract that would stipulate that by simply submitting my article to their email address I give away my entire rights to my original work to them (not that my work is really copyrighted by law), and thirdly, the other two magazines received my work directly from me. Am I right? Please let me know.

Thank you very much in advance.
Sincerely,
SA Received on Mon Jun 20 2005 - 20:05:01 GMT